Merge remote-tracking branch 'bp/master'

examples/SharedMemory/PhysicsClient.h

@@ -37,6 +37,8 @@ public:
     virtual int getNumUserConstraints() const = 0;
     
     virtual int getUserConstraintInfo(int constraintUniqueId, struct b3UserConstraint& info) const = 0;
+	
+	virtual int getUserConstraintId(int serialIndex) const = 0;
     
     virtual void setSharedMemoryKey(int key) = 0;
 

examples/SharedMemory/PhysicsClientC_API.cpp

@@ -1179,6 +1179,13 @@ int b3GetUserConstraintInfo(b3PhysicsClientHandle physClient, int constraintUniq
     return 0;
 }
 
+/// return the user constraint id, given the index in range [0 , b3GetNumUserConstraints() )
+int b3GetUserConstraintId(b3PhysicsClientHandle physClient, int serialIndex)
+{
+	PhysicsClient* cl = (PhysicsClient* ) physClient;
+	return cl->getUserConstraintId(serialIndex);
+}
+
 /// return the body unique id, given the index in range [0 , b3GetNumBodies() )
 int b3GetBodyUniqueId(b3PhysicsClientHandle physClient, int serialIndex)
 {
@@ -1208,7 +1215,41 @@ int	b3GetJointInfo(b3PhysicsClientHandle physClient, int bodyIndex, int jointInd
 	return cl->getJointInfo(bodyIndex, jointIndex, *info);
 }
 
+b3SharedMemoryCommandHandle b3InitResetDynamicInfo(b3PhysicsClientHandle physClient)
+{
+	PhysicsClient* cl = (PhysicsClient* ) physClient;
+	b3Assert(cl);
+	b3Assert(cl->canSubmitCommand());
+	struct SharedMemoryCommand* command = cl->getAvailableSharedMemoryCommand();
+	b3Assert(command);
+	command->m_type = CMD_RESET_DYNAMIC_INFO;
+	command->m_updateFlags = 0;
+	
+	return (b3SharedMemoryCommandHandle) command;
+}
 
+int b3ResetDynamicInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass)
+{
+	struct SharedMemoryCommand* command = (struct SharedMemoryCommand*) commandHandle;
+	b3Assert(command->m_type == CMD_RESET_DYNAMIC_INFO);
+	b3Assert(mass > 0);
+	command->m_resetDynamicInfoArgs.m_bodyUniqueId = bodyUniqueId;
+	command->m_resetDynamicInfoArgs.m_linkIndex = linkIndex;
+	command->m_resetDynamicInfoArgs.m_mass = mass;
+	command->m_updateFlags |= RESET_DYNAMIC_INFO_SET_MASS;
+	return 0;
+}
+
+int b3ResetDynamicInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction)
+{
+	struct SharedMemoryCommand* command = (struct SharedMemoryCommand*) commandHandle;
+	b3Assert(command->m_type == CMD_RESET_DYNAMIC_INFO);
+	command->m_resetDynamicInfoArgs.m_bodyUniqueId = bodyUniqueId;
+	command->m_resetDynamicInfoArgs.m_linkIndex = linkIndex;
+	command->m_resetDynamicInfoArgs.m_lateralFriction = lateralFriction;
+	command->m_updateFlags |= RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION;
+	return 0;
+}
 
 b3SharedMemoryCommandHandle b3InitCreateUserConstraintCommand(b3PhysicsClientHandle physClient, int parentBodyIndex, int parentJointIndex, int childBodyIndex, int childJointIndex, struct b3JointInfo* info)
 {

examples/SharedMemory/PhysicsClientC_API.h

@@ -76,6 +76,13 @@ int	b3GetNumJoints(b3PhysicsClientHandle physClient, int bodyIndex);
 
 ///given a body and joint index, return the joint information. See b3JointInfo in SharedMemoryPublic.h
 int	b3GetJointInfo(b3PhysicsClientHandle physClient, int bodyIndex, int jointIndex, struct b3JointInfo* info);
+
+///given a body unique id and link index, return the dynamic information. See b3DynamicInfo in SharedMemoryPublic.h
+int b3GetDynamicInfo(b3PhysicsClientHandle physClient, int bodyUniqueId, int linkIndex, struct b3DynamicInfo* info);
+	
+b3SharedMemoryCommandHandle b3InitResetDynamicInfo(b3PhysicsClientHandle physClient);
+int b3ResetDynamicInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass);
+int b3ResetDynamicInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction);
     
 b3SharedMemoryCommandHandle b3InitCreateUserConstraintCommand(b3PhysicsClientHandle physClient, int parentBodyIndex, int parentJointIndex, int childBodyIndex, int childJointIndex, struct b3JointInfo* info);
 
@@ -92,6 +99,8 @@ b3SharedMemoryCommandHandle  b3InitRemoveUserConstraintCommand(b3PhysicsClientHa
 
 int b3GetNumUserConstraints(b3PhysicsClientHandle physClient);
 int b3GetUserConstraintInfo(b3PhysicsClientHandle physClient, int constraintUniqueId, struct b3UserConstraint* info);
+/// return the user constraint id, given the index in range [0 , b3GetNumUserConstraints() )
+int b3GetUserConstraintId(b3PhysicsClientHandle physClient, int serialIndex);
     
 ///Request physics debug lines for debug visualization. The flags in debugMode are the same as used in Bullet
 ///See btIDebugDraw::DebugDrawModes in Bullet/src/LinearMath/btIDebugDraw.h

examples/SharedMemory/PhysicsClientSharedMemory.cpp

@@ -163,6 +163,15 @@ int PhysicsClientSharedMemory::getUserConstraintInfo(int constraintUniqueId, str
     return 0;
 }
 
+int PhysicsClientSharedMemory::getUserConstraintId(int serialIndex) const
+{
+	if ((serialIndex >= 0) && (serialIndex < getNumUserConstraints()))
+	{
+		return m_data->m_userConstraintInfoMap.getKeyAtIndex(serialIndex).getUid1();
+	}
+	return -1;
+}
+
 PhysicsClientSharedMemory::PhysicsClientSharedMemory()
 
 {

examples/SharedMemory/PhysicsClientSharedMemory.h

@@ -48,6 +48,8 @@ public:
     virtual int getNumUserConstraints() const;
     
     virtual int getUserConstraintInfo(int constraintUniqueId, struct b3UserConstraint& info) const;
+	
+	virtual int getUserConstraintId(int serialIndex) const;
     
     virtual void setSharedMemoryKey(int key);
 

examples/SharedMemory/PhysicsDirect.cpp

@@ -961,7 +961,14 @@ int PhysicsDirect::getUserConstraintInfo(int constraintUniqueId, struct b3UserCo
     return 0;
 }
 
-
+int PhysicsDirect::getUserConstraintId(int serialIndex) const
+{
+	if ((serialIndex >= 0) && (serialIndex < getNumUserConstraints()))
+	{
+		return m_data->m_userConstraintInfoMap.getKeyAtIndex(serialIndex).getUid1();
+	}
+	return -1;
+}
 
 int PhysicsDirect::getBodyUniqueId(int serialIndex) const
 {

examples/SharedMemory/PhysicsDirect.h

@@ -69,6 +69,8 @@ public:
     virtual int getNumUserConstraints() const;
     
     virtual int getUserConstraintInfo(int constraintUniqueId, struct b3UserConstraint& info) const;
+	
+	virtual int getUserConstraintId(int serialIndex) const;
     
 	///todo: move this out of the
     virtual void setSharedMemoryKey(int key);

examples/SharedMemory/PhysicsLoopBack.cpp

@@ -108,6 +108,11 @@ int PhysicsLoopBack::getUserConstraintInfo(int constraintUniqueId, struct b3User
     return m_data->m_physicsClient->getUserConstraintInfo( constraintUniqueId, info);
 }
 
+int PhysicsLoopBack::getUserConstraintId(int serialIndex) const
+{
+	return m_data->m_physicsClient->getUserConstraintId(serialIndex);
+}
+
 ///todo: move this out of the interface
 void PhysicsLoopBack::setSharedMemoryKey(int key)
 {

examples/SharedMemory/PhysicsLoopBack.h

@@ -51,6 +51,8 @@ public:
     virtual int getNumUserConstraints() const;
     
     virtual int getUserConstraintInfo(int constraintUniqueId, struct b3UserConstraint&info) const;
+	
+	virtual int getUserConstraintId(int serialIndex) const;
     
 	///todo: move this out of the
     virtual void setSharedMemoryKey(int key);

examples/SharedMemory/PhysicsServerCommandProcessor.cpp

@@ -3818,6 +3818,63 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
 
 					break;
 				};
+				case CMD_RESET_DYNAMIC_INFO:
+				{
+					BT_PROFILE("CMD_RESET_DYNAMIC_INFO");
+					
+					if (clientCmd.m_updateFlags & RESET_DYNAMIC_INFO_SET_MASS)
+					{
+						int bodyUniqueId = clientCmd.m_resetDynamicInfoArgs.m_bodyUniqueId;
+						int linkIndex = clientCmd.m_resetDynamicInfoArgs.m_linkIndex;
+						double mass = clientCmd.m_resetDynamicInfoArgs.m_mass;
+						btAssert(bodyUniqueId >= 0);
+						btAssert(linkIndex >= -1);
+						
+						InteralBodyData* body = m_data->getHandle(bodyUniqueId);
+						if (body && body->m_multiBody)
+						{
+							btMultiBody* mb = body->m_multiBody;
+							if (linkIndex == -1)
+							{
+								mb->setBaseMass(mass);
+							}
+							else
+							{
+								mb->getLink(linkIndex).m_mass = mass;
+							}
+						}
+					}
+					
+					if (clientCmd.m_updateFlags & RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION)
+					{
+						int bodyUniqueId = clientCmd.m_resetDynamicInfoArgs.m_bodyUniqueId;
+						int linkIndex = clientCmd.m_resetDynamicInfoArgs.m_linkIndex;
+						double lateralFriction = clientCmd.m_resetDynamicInfoArgs.m_lateralFriction;
+						btAssert(bodyUniqueId >= 0);
+						btAssert(linkIndex >= -1);
+						
+						InteralBodyData* body = m_data->getHandle(bodyUniqueId);
+						if (body && body->m_multiBody)
+						{
+							btMultiBody* mb = body->m_multiBody;
+							if (linkIndex == -1)
+							{
+								mb->getBaseCollider()->setFriction(lateralFriction);
+							}
+							else
+							{
+								mb->getLinkCollider(linkIndex)->setFriction(lateralFriction);
+							}
+						}
+					}
+
+					
+					SharedMemoryStatus& serverCmd =serverStatusOut;
+					serverCmd.m_type = CMD_CLIENT_COMMAND_COMPLETED;
+					hasStatus = true;
+					
+					break;
+				};
 				case CMD_SEND_PHYSICS_SIMULATION_PARAMETERS:
 				{
 					BT_PROFILE("CMD_SEND_PHYSICS_SIMULATION_PARAMETERS");

examples/SharedMemory/PhysicsServerExample.cpp

@@ -1203,39 +1203,45 @@ public:
 			printf("key[%d]=%d state = %d\n",i,m_args[0].m_keyboardEvents[i].m_keyCode,m_args[0].m_keyboardEvents[i].m_keyState);
 		}
 		*/
+		double shift=0.1;
+
+		CommonWindowInterface* window = m_guiHelper->getAppInterface()->m_window;
+		if (window->isModifierKeyPressed(B3G_SHIFT))
+			shift=0.01;
+
 		if (key=='w' && state)
 		{
-			gVRTeleportPos1[0]+=0.1;
+			gVRTeleportPos1[0]+=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='s' && state)
 		{
-			gVRTeleportPos1[0]-=0.1;
+			gVRTeleportPos1[0]-=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='a' && state)
 		{
-			gVRTeleportPos1[1]-=0.1;
+			gVRTeleportPos1[1]-=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='d' && state)
 		{
-			gVRTeleportPos1[1]+=0.1;
+			gVRTeleportPos1[1]+=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='q' && state)
 		{
-			gVRTeleportPos1[2]+=0.1;
+			gVRTeleportPos1[2]+=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='e' && state)
 		{
-			gVRTeleportPos1[2]-=0.1;
+			gVRTeleportPos1[2]-=shift;
 			saveCurrentSettingsVR();
 		}
 		if (key=='z' && state)
 		{
-			gVRTeleportRotZ+=0.1;
+			gVRTeleportRotZ+=shift;
 			gVRTeleportOrn = btQuaternion(btVector3(0, 0, 1), gVRTeleportRotZ);
 			saveCurrentSettingsVR();
 		}

examples/SharedMemory/SharedMemoryCommands.h

@@ -106,6 +106,22 @@ struct BulletDataStreamArgs
 	char m_bodyName[MAX_FILENAME_LENGTH];
 };
 
+enum EnumResetDynamicInfoFlags
+{
+	RESET_DYNAMIC_INFO_SET_MASS=1,
+	RESET_DYNAMIC_INFO_SET_COM=2,
+	RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION=4,
+};
+
+struct ResetDynamicInfoArgs
+{
+	int m_bodyUniqueId;
+	int m_linkIndex;
+	double m_mass;
+	double m_COM[3];
+	double m_lateralFriction;
+};
+
 struct SetJointFeedbackArgs
 {
 	int m_bodyUniqueId;
@@ -714,6 +730,7 @@ struct SharedMemoryCommand
 		struct MjcfArgs	m_mjcfArguments;
 		struct FileArgs m_fileArguments;
 		struct SdfRequestInfoArgs m_sdfRequestInfoArgs;
+		struct ResetDynamicInfoArgs m_resetDynamicInfoArgs;
 		struct InitPoseArgs m_initPoseArgs;
 		struct SendPhysicsSimulationParameters m_physSimParamArgs;
 		struct BulletDataStreamArgs	m_dataStreamArguments;

examples/SharedMemory/SharedMemoryPublic.h

@@ -56,6 +56,7 @@ enum EnumSharedMemoryClientCommand
 	CMD_REQUEST_KEYBOARD_EVENTS_DATA,
 	CMD_REQUEST_OPENGL_VISUALIZER_CAMERA,
 	CMD_REMOVE_BODY,
+	CMD_RESET_DYNAMIC_INFO,
     //don't go beyond this command!
     CMD_MAX_CLIENT_COMMANDS,
     
@@ -218,6 +219,11 @@ struct b3BodyInfo
 	const char* m_bodyName; // for btRigidBody, it does not have a base, but can still have a body name from urdf
 };
 
+struct b3DynamicInfo
+{
+	double m_mass;
+	double m_localInertialPosition[3];
+};
 
 // copied from btMultiBodyLink.h
 enum SensorType {

examples/pybullet/examples/constraint.py

@@ -9,6 +9,8 @@ cubeId = p.loadURDF("cube_small.urdf",0,0,1)
 p.setGravity(0,0,-10)
 p.setRealTimeSimulation(1)
 cid = p.createConstraint(cubeId,-1,-1,-1,p.JOINT_FIXED,[0,0,0],[0,0,0],[0,0,1])
+print cid
+print p.getConstraintUniqueId(0)
 prev=[0,0,1]
 a=-math.pi
 while 1:
@@ -21,4 +23,4 @@ while 1:
 	orn = p.getQuaternionFromEuler([a,0,0])
 	p.changeConstraint(cid,pivot,jointChildFrameOrientation=orn, maxForce=50)
 
-p.removeConstraint(cid)
+p.removeConstraint(cid)

examples/pybullet/examples/reset_dynamic_info.py

@@ -0,0 +1,20 @@
+import pybullet as p
+import time
+import math
+
+p.connect(p.GUI)
+
+p.loadURDF(fileName="plane.urdf",baseOrientation=[0.25882,0,0,0.96593])
+p.loadURDF(fileName="cube.urdf",baseOrientation=[0.25882,0,0,0.96593],basePosition=[0,0,2])
+p.loadURDF(fileName="cube.urdf",baseOrientation=[0,0,0,1],basePosition=[0,0,4])
+p.resetDynamicInfo(bodyUniqueId=2,linkIndex=-1,mass=0.1)
+#p.resetDynamicInfo(bodyUniqueId=2,linkIndex=-1,mass=100.0)
+p.setGravity(0,0,-10)
+p.setRealTimeSimulation(0)
+t=0
+while 1:
+	t=t+1
+	if t > 400:
+		p.resetDynamicInfo(bodyUniqueId=0,linkIndex=-1,lateralFriction=0.01)
+	time.sleep(.01)
+	p.stepSimulation()

examples/pybullet/gym/agents/actor_net.py

@@ -0,0 +1,21 @@
+"""An actor network."""
+import tensorflow as tf
+import sonnet as snt
+
+class ActorNetwork(snt.AbstractModule):
+  """An actor network as a sonnet Module."""
+
+  def __init__(self, layer_sizes, action_size, name='target_actor'):
+    super(ActorNetwork, self).__init__(name=name)
+    self._layer_sizes = layer_sizes
+    self._action_size = action_size
+
+  def _build(self, inputs):
+    state = inputs
+    for output_size in self._layer_sizes:
+      state = snt.Linear(output_size)(state)
+      state = tf.nn.relu(state)
+
+    action = tf.tanh(
+        snt.Linear(self._action_size, name='action')(state))
+    return action

examples/pybullet/gym/agents/simpleAgent.py

@@ -0,0 +1,46 @@
+"""Loads a DDPG agent without too much external dependencies
+"""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import os
+import collections
+import numpy as np
+import tensorflow as tf
+
+import sonnet as snt
+from agents import actor_net
+
+class SimpleAgent():
+  def __init__(
+      self,
+      session,
+      ckpt_path,
+      actor_layer_size,
+      observation_size=(31,),
+      action_size=8,
+  ):
+    self._ckpt_path = ckpt_path
+    self._actor_layer_size = actor_layer_size
+    self._observation_size = observation_size
+    self._action_size = action_size
+    self._session = session
+    self._build()
+
+  def _build(self):
+    self._agent_net = actor_net.ActorNetwork(self._actor_layer_size, self._action_size)
+    self._obs = tf.placeholder(tf.float32, (31,))
+    with tf.name_scope('Act'):
+      batch_obs = snt.nest.pack_iterable_as(self._obs,
+                                            snt.nest.map(lambda x: tf.expand_dims(x, 0),
+                                                         snt.nest.flatten_iterable(self._obs)))
+      self._action = self._agent_net(batch_obs)
+      saver = tf.train.Saver()
+      saver.restore(
+          sess=self._session,
+          save_path=self._ckpt_path)
+
+  def __call__(self, observation):
+    out_action = self._session.run(self._action, feed_dict={self._obs: observation})
+    return out_action[0]

examples/pybullet/gym/data/agent/tf_graph_data/checkpoint

@@ -0,0 +1,2 @@
+model_checkpoint_path: "/cns/ij-d/home/jietan/persistent/minitaur/minitaur_vizier_3_153645653/Bullet/MinitaurSimEnv/28158/0003600000/agent/tf_graph_data/tf_graph_data.ckpt"
+all_model_checkpoint_paths: "/cns/ij-d/home/jietan/persistent/minitaur/minitaur_vizier_3_153645653/Bullet/MinitaurSimEnv/28158/0003600000/agent/tf_graph_data/tf_graph_data.ckpt"

examples/pybullet/gym/envs/bullet/minitaurGymEnv.py

@@ -0,0 +1,109 @@
+import math
+import gym
+from gym import spaces
+from gym.utils import seeding
+import numpy as np
+import time
+import pybullet as p
+import minitaur_new
+
+class MinitaurGymEnv(gym.Env):
+  metadata = {
+      'render.modes': ['human', 'rgb_array'],
+      'video.frames_per_second' : 50
+  }
+
+  def __init__(self,
+               urdfRoot="",
+               actionRepeat=1,
+               render=False):
+    self._timeStep = 0.01
+    self._urdfRoot = urdfRoot
+    self._actionRepeat = actionRepeat
+    self._observation = []
+    self._envStepCounter = 0
+    self._render = render
+    self._lastBasePosition = [0, 0, 0]
+    if self._render:
+      p.connect(p.GUI)
+    else:
+      p.connect(p.DIRECT)
+    self._seed()
+    self.reset()
+    observationDim = self._minitaur.getObservationDimension()
+    observation_high = np.array([np.finfo(np.float32).max] * observationDim)
+    actionDim = 8
+    action_high = np.array([1] * actionDim)
+    self.action_space = spaces.Box(-action_high, action_high)
+    self.observation_space = spaces.Box(-observation_high, observation_high)
+    self.viewer = None
+
+  def _reset(self):
+    p.resetSimulation()
+    p.setPhysicsEngineParameter(numSolverIterations=300)
+    p.setTimeStep(self._timeStep)
+    p.loadURDF("%splane.urdf" % self._urdfRoot)
+    p.setGravity(0,0,-10)
+    self._minitaur = minitaur_new.Minitaur(self._urdfRoot)
+    self._envStepCounter = 0
+    self._lastBasePosition = [0, 0, 0]
+    for i in range(100):
+      p.stepSimulation()
+    self._observation = self._minitaur.getObservation()
+    return self._observation
+
+  def __del__(self):
+    p.disconnect()
+
+  def _seed(self, seed=None):
+    self.np_random, seed = seeding.np_random(seed)
+    return [seed]
+
+  def _step(self, action):
+    if (self._render):
+      basePos = self._minitaur.getBasePosition()
+      p.resetDebugVisualizerCamera(1, 30, 40, basePos)
+
+    if len(action) != self._minitaur.getActionDimension():
+      raise ValueError("We expect {} continuous action not {}.".format(self._minitaur.getActionDimension(), len(action)))
+
+    for i in range(len(action)):
+      if not -1.01 <= action[i] <= 1.01:
+        raise ValueError("{}th action should be between -1 and 1 not {}.".format(i, action[i]))
+
+    realAction = self._minitaur.convertFromLegModel(action)
+    self._minitaur.applyAction(realAction)
+    for i in range(self._actionRepeat):
+      p.stepSimulation()
+      if self._render:
+        time.sleep(self._timeStep)
+      self._observation = self._minitaur.getObservation()
+      if self._termination():
+        break
+      self._envStepCounter += 1
+    reward = self._reward()
+    done = self._termination()
+    return np.array(self._observation), reward, done, {}
+
+  def _render(self, mode='human', close=False):
+      return
+
+  def is_fallen(self):
+    orientation = self._minitaur.getBaseOrientation()
+    rotMat = p.getMatrixFromQuaternion(orientation)
+    localUp = rotMat[6:]
+    return np.dot(np.asarray([0, 0, 1]), np.asarray(localUp)) < 0 or self._observation[-1] < 0.1
+
+  def _termination(self):
+    return self.is_fallen()
+
+  def _reward(self):
+    currentBasePosition = self._minitaur.getBasePosition()
+    forward_reward = currentBasePosition[0] - self._lastBasePosition[0]
+    self._lastBasePosition = currentBasePosition
+
+    energyWeight = 0.001
+    energy = np.abs(np.dot(self._minitaur.getMotorTorques(), self._minitaur.getMotorVelocities())) * self._timeStep
+    energy_reward = energyWeight * energy
+    reward = forward_reward - energy_reward
+    return reward

examples/pybullet/gym/envs/bullet/minitaur_new.py

@@ -0,0 +1,166 @@
+import pybullet as p
+import numpy as np
+import copy
+import math
+
+class Minitaur:
+  def __init__(self, urdfRootPath=''):
+    self.urdfRootPath = urdfRootPath
+    self.reset()
+
+  def buildJointNameToIdDict(self):
+    nJoints = p.getNumJoints(self.quadruped)
+    self.jointNameToId = {}
+    for i in range(nJoints):
+      jointInfo = p.getJointInfo(self.quadruped, i)
+      self.jointNameToId[jointInfo[1].decode('UTF-8')] = jointInfo[0]
+    self.resetPose()
+
+  def buildMotorIdList(self):
+    self.motorIdList.append(self.jointNameToId['motor_front_leftL_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_front_leftR_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_back_leftL_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_back_leftR_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_front_rightL_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_front_rightR_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_back_rightL_joint'])
+    self.motorIdList.append(self.jointNameToId['motor_back_rightR_joint'])
+
+  def reset(self):
+#    self.quadruped = p.loadURDF("%squadruped/minitaur.urdf" % self.urdfRootPath, [0,0,.2], flags=p.URDF_USE_SELF_COLLISION)
+    self.quadruped = p.loadURDF("%squadruped/minitaur.urdf" % self.urdfRootPath, [0,0,.2])
+    self.kp = 1
+    self.kd = 1
+    self.maxForce = 3.5
+    self.nMotors = 8
+    self.motorIdList = []
+    self.motorDir = [-1, -1, -1, -1, 1, 1, 1, 1]
+    self.buildJointNameToIdDict()
+    self.buildMotorIdList()
+
+
+  def setMotorAngleById(self, motorId, desiredAngle):
+    p.setJointMotorControl2(bodyIndex=self.quadruped, jointIndex=motorId, controlMode=p.POSITION_CONTROL, targetPosition=desiredAngle, positionGain=self.kp, velocityGain=self.kd, force=self.maxForce)
+
+  def setMotorAngleByName(self, motorName, desiredAngle):
+    self.setMotorAngleById(self.jointNameToId[motorName], desiredAngle)
+
+  def resetPose(self):
+    kneeFrictionForce = 0
+    halfpi = 1.57079632679
+    kneeangle = -2.1834 #halfpi - acos(upper_leg_length / lower_leg_length)
+
+    #left front leg
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_front_leftL_joint'],self.motorDir[0]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_front_leftL_link'],self.motorDir[0]*kneeangle)
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_front_leftR_joint'],self.motorDir[1]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_front_leftR_link'],self.motorDir[1]*kneeangle)
+    p.createConstraint(self.quadruped,self.jointNameToId['knee_front_leftR_link'],self.quadruped,self.jointNameToId['knee_front_leftL_link'],p.JOINT_POINT2POINT,[0,0,0],[0,0.005,0.2],[0,0.01,0.2])
+    self.setMotorAngleByName('motor_front_leftL_joint', self.motorDir[0]*halfpi)
+    self.setMotorAngleByName('motor_front_leftR_joint', self.motorDir[1]*halfpi)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_front_leftL_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_front_leftR_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+
+    #left back leg
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_back_leftL_joint'],self.motorDir[2]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_back_leftL_link'],self.motorDir[2]*kneeangle)
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_back_leftR_joint'],self.motorDir[3]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_back_leftR_link'],self.motorDir[3]*kneeangle)
+    p.createConstraint(self.quadruped,self.jointNameToId['knee_back_leftR_link'],self.quadruped,self.jointNameToId['knee_back_leftL_link'],p.JOINT_POINT2POINT,[0,0,0],[0,0.005,0.2],[0,0.01,0.2])
+    self.setMotorAngleByName('motor_back_leftL_joint',self.motorDir[2]*halfpi)
+    self.setMotorAngleByName('motor_back_leftR_joint',self.motorDir[3]*halfpi)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_back_leftL_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_back_leftR_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+ 
+    #right front leg
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_front_rightL_joint'],self.motorDir[4]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_front_rightL_link'],self.motorDir[4]*kneeangle)
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_front_rightR_joint'],self.motorDir[5]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_front_rightR_link'],self.motorDir[5]*kneeangle)
+    p.createConstraint(self.quadruped,self.jointNameToId['knee_front_rightR_link'],self.quadruped,self.jointNameToId['knee_front_rightL_link'],p.JOINT_POINT2POINT,[0,0,0],[0,0.005,0.2],[0,0.01,0.2])
+    self.setMotorAngleByName('motor_front_rightL_joint',self.motorDir[4]*halfpi)
+    self.setMotorAngleByName('motor_front_rightR_joint',self.motorDir[5]*halfpi)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_front_rightL_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_front_rightR_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+ 
+
+    #right back leg
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_back_rightL_joint'],self.motorDir[6]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_back_rightL_link'],self.motorDir[6]*kneeangle)
+    p.resetJointState(self.quadruped,self.jointNameToId['motor_back_rightR_joint'],self.motorDir[7]*halfpi)
+    p.resetJointState(self.quadruped,self.jointNameToId['knee_back_rightR_link'],self.motorDir[7]*kneeangle)
+    p.createConstraint(self.quadruped,self.jointNameToId['knee_back_rightR_link'],self.quadruped,self.jointNameToId['knee_back_rightL_link'],p.JOINT_POINT2POINT,[0,0,0],[0,0.005,0.2],[0,0.01,0.2])
+    self.setMotorAngleByName('motor_back_rightL_joint',self.motorDir[6]*halfpi)
+    self.setMotorAngleByName('motor_back_rightR_joint',self.motorDir[7]*halfpi)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_back_rightL_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+    p.setJointMotorControl2(bodyIndex=self.quadruped,jointIndex=self.jointNameToId['knee_back_rightR_link'],controlMode=p.VELOCITY_CONTROL,targetVelocity=0,force=kneeFrictionForce)
+
+
+  def getBasePosition(self):
+    position, orientation = p.getBasePositionAndOrientation(self.quadruped)
+    return position
+
+  def getBaseOrientation(self):
+    position, orientation = p.getBasePositionAndOrientation(self.quadruped)
+    return orientation
+
+  def getActionDimension(self):
+    return self.nMotors
+
+  def getObservationDimension(self):
+    return len(self.getObservation())
+
+  def getObservation(self):
+    observation = []
+    observation.extend(self.getMotorAngles().tolist())
+    observation.extend(self.getMotorVelocities().tolist())
+    observation.extend(self.getMotorTorques().tolist())
+    observation.extend(list(self.getBaseOrientation()))
+    observation.extend(list(self.getBasePosition()))
+    return observation
+
+
+  def applyAction(self, motorCommands):
+    motorCommandsWithDir = np.multiply(motorCommands, self.motorDir)
+#    print('action: {}'.format(motorCommands))
+#    print('motor: {}'.format(motorCommandsWithDir))
+    for i in range(self.nMotors):
+      self.setMotorAngleById(self.motorIdList[i], motorCommandsWithDir[i])
+
+  def getMotorAngles(self):
+    motorAngles = []
+    for i in range(self.nMotors):
+      jointState = p.getJointState(self.quadruped, self.motorIdList[i])
+      motorAngles.append(jointState[0])
+    motorAngles = np.multiply(motorAngles, self.motorDir)
+    return motorAngles
+
+  def getMotorVelocities(self):
+    motorVelocities = []
+    for i in range(self.nMotors):
+      jointState = p.getJointState(self.quadruped, self.motorIdList[i])
+      motorVelocities.append(jointState[1])
+    motorVelocities = np.multiply(motorVelocities, self.motorDir)
+    return motorVelocities
+
+  def getMotorTorques(self):
+    motorTorques = []
+    for i in range(self.nMotors):
+      jointState = p.getJointState(self.quadruped, self.motorIdList[i])
+      motorTorques.append(jointState[3])
+    motorTorques = np.multiply(motorTorques, self.motorDir)
+    return motorTorques
+
+  def convertFromLegModel(self, actions):
+    motorAngle = copy.deepcopy(actions)
+    scaleForSingularity = 1
+    offsetForSingularity = 0.5
+    motorAngle[0] = math.pi + math.pi / 4 * actions[0] - scaleForSingularity * math.pi / 4 * (actions[4] + 1 + offsetForSingularity)
+    motorAngle[1] = math.pi - math.pi / 4 * actions[0] - scaleForSingularity * math.pi / 4 * (actions[4] + 1 + offsetForSingularity)
+    motorAngle[2] = math.pi + math.pi / 4 * actions[1] - scaleForSingularity * math.pi / 4 * (actions[5] + 1 + offsetForSingularity)
+    motorAngle[3] = math.pi - math.pi / 4 * actions[1] - scaleForSingularity * math.pi / 4 * (actions[5] + 1 + offsetForSingularity)
+    motorAngle[4] = math.pi - math.pi / 4 * actions[2] - scaleForSingularity * math.pi / 4 * (actions[6] + 1 + offsetForSingularity)
+    motorAngle[5] = math.pi + math.pi / 4 * actions[2] - scaleForSingularity * math.pi / 4 * (actions[6] + 1 + offsetForSingularity)
+    motorAngle[6] = math.pi - math.pi / 4 * actions[3] - scaleForSingularity * math.pi / 4 * (actions[7] + 1 + offsetForSingularity)
+    motorAngle[7] = math.pi + math.pi / 4 * actions[3] - scaleForSingularity * math.pi / 4 * (actions[7] + 1 + offsetForSingularity)
+    return motorAngle

examples/pybullet/gym/minitaurGymEnvTest.py

@@ -0,0 +1,85 @@
+'''
+A test for minitaurGymEnv
+'''
+
+import gym
+import numpy as np
+import math
+
+import numpy as np
+import tensorflow as tf
+
+from envs.bullet.minitaurGymEnv import MinitaurGymEnv
+from agents import simpleAgent
+
+def testSinePolicy():
+  """Tests sine policy
+    """
+  np.random.seed(47)
+
+  environment = MinitaurGymEnv(render=True)
+  sum_reward = 0
+  steps = 1000
+  amplitude1Bound = 0.5
+  amplitude2Bound = 0.15
+  speed = 40
+
+  for stepCounter in range(steps):
+    t = float(stepCounter) * environment._timeStep
+
+    if (t < 1):
+      amplitude1 = 0
+      amplitude2 = 0
+    else:
+      amplitude1 = amplitude1Bound
+      amplitude2 = amplitude2Bound
+    a1 = math.sin(t*speed)*amplitude1
+    a2 = math.sin(t*speed+3.14)*amplitude1
+    a3 = math.sin(t*speed)*amplitude2
+    a4 = math.sin(t*speed+3.14)*amplitude2
+
+    action = [a1, a2, a2, a1, a3, a4, a4, a3]
+
+    state, reward, done, info = environment.step(action)
+    sum_reward += reward
+    if done:
+      environment.reset()
+      print("sum reward: ", sum_reward)
+
+
+def testDDPGPolicy():
+  """Tests sine policy
+    """
+  environment = MinitaurGymEnv(render=True)
+  sum_reward = 0
+  steps = 1000
+  ckpt_path = 'data/agent/tf_graph_data/tf_graph_data.ckpt'
+  observation_shape = (31,)
+  action_size = 8
+  actor_layer_sizes = (100, 181)
+  n_steps = 0
+  tf.reset_default_graph()
+  with tf.Session() as session:
+    agent = simpleAgent.SimpleAgent(session, ckpt_path,
+                                    actor_layer_sizes,
+                                    observation_size=observation_shape,
+                                    action_size=action_size)
+    state = environment.reset()
+    action = agent(state)
+    for _ in range(steps):
+      n_steps += 1
+      state, reward, done, info = environment.step(action)
+      action = agent(state)
+      sum_reward += reward
+      if done:
+        environment.reset()
+        n_steps += 1
+        print("total reward: ", sum_reward)
+        print("total steps:  ", n_steps)
+        sum_reward = 0
+        n_steps = 0
+        return
+
+
+testDDPGPolicy()
+#testSinePolicy()

examples/pybullet/pybullet.c

@@ -604,6 +604,49 @@ static PyObject* pybullet_loadMJCF(PyObject* self, PyObject* args, PyObject* key
 	return pylist;
 }
 
+static PyObject* pybullet_resetDynamicInfo(PyObject* self, PyObject* args, PyObject* keywds)
+{
+	int bodyUniqueId = -1;
+	int linkIndex = -2;
+	double mass = -1;
+	double lateralFriction = -1;
+	b3PhysicsClientHandle sm = 0;
+	
+	int physicsClientId = 0;
+	static char* kwlist[] = {"bodyUniqueId", "linkIndex", "mass", "lateralFriction", "physicsClientId", NULL};
+	if (!PyArg_ParseTupleAndKeywords(args, keywds, "ii|ddi", kwlist, &bodyUniqueId, &linkIndex,&mass, &lateralFriction, &physicsClientId))
+	{
+		return NULL;
+	}
+	
+	sm = getPhysicsClient(physicsClientId);
+	if (sm == 0)
+	{
+		PyErr_SetString(SpamError, "Not connected to physics server.");
+		return NULL;
+	}
+	
+	{
+		b3SharedMemoryCommandHandle command = b3InitResetDynamicInfo(sm);
+		b3SharedMemoryStatusHandle statusHandle;
+		
+		if (mass >= 0)
+		{
+			b3ResetDynamicInfoSetMass(command, bodyUniqueId, linkIndex, mass);
+		}
+		
+		if (lateralFriction >= 0)
+		{
+			b3ResetDynamicInfoSetLateralFriction(command, bodyUniqueId, linkIndex, lateralFriction);
+		}
+		
+		statusHandle = b3SubmitClientCommandAndWaitStatus(sm, command);
+	}
+	
+	Py_INCREF(Py_None);
+	return Py_None;
+}
+
 static PyObject* pybullet_setPhysicsEngineParameter(PyObject* self, PyObject* args, PyObject* keywds)
 {
 	double fixedTimeStep = -1;
@@ -1843,6 +1886,36 @@ static PyObject* pybullet_getConstraintInfo(PyObject* self, PyObject* args, PyOb
 	return NULL;
 }
 
+static PyObject* pybullet_getConstraintUniqueId(PyObject* self, PyObject* args, PyObject* keywds)
+{
+	int physicsClientId = 0;
+	int serialIndex = -1;
+	b3PhysicsClientHandle sm = 0;
+	
+	static char* kwlist[] = {"serialIndex", "physicsClientId", NULL};
+	if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|i", kwlist, &serialIndex, &physicsClientId))
+	{
+		return NULL;
+	}
+	sm = getPhysicsClient(physicsClientId);
+	if (sm == 0)
+	{
+		PyErr_SetString(SpamError, "Not connected to physics server.");
+		return NULL;
+	}
+	
+	{
+		int userConstraintId = -1;
+		userConstraintId = b3GetUserConstraintId(sm, serialIndex);
+		
+#if PY_MAJOR_VERSION >= 3
+		return PyLong_FromLong(userConstraintId);
+#else
+		return PyInt_FromLong(userConstraintId);
+#endif
+	}
+}
+
 static PyObject* pybullet_getNumConstraints(PyObject* self, PyObject* args, PyObject* keywds)
 {
 	int numConstraints = 0;
@@ -5430,7 +5503,7 @@ static PyMethodDef SpamMethods[] = {
 	{"getConstraintInfo", (PyCFunction)pybullet_getConstraintInfo, METH_VARARGS | METH_KEYWORDS,
 	 "Get the user-created constraint info, given a constraint unique id."},
 
-	{"getConstraintUniqueId", (PyCFunction)pybullet_getBodyUniqueId, METH_VARARGS | METH_KEYWORDS,
+	{"getConstraintUniqueId", (PyCFunction)pybullet_getConstraintUniqueId, METH_VARARGS | METH_KEYWORDS,
 	 "Get the unique id of the constraint, given a integer index in range [0.. number of constraints)."},
 
 	{"getBasePositionAndOrientation", (PyCFunction)pybullet_getBasePositionAndOrientation,
@@ -5472,6 +5545,9 @@ static PyMethodDef SpamMethods[] = {
 	{"resetJointState", (PyCFunction)pybullet_resetJointState, METH_VARARGS | METH_KEYWORDS,
 	 "Reset the state (position, velocity etc) for a joint on a body "
 	 "instantaneously, not through physics simulation."},
+	
+	{"resetDynamicInfo", (PyCFunction)pybullet_resetDynamicInfo, METH_VARARGS | METH_KEYWORDS,
+	 "Reset dynamic information such as mass, lateral friction coefficient."},
 
 	{"setJointMotorControl", (PyCFunction)pybullet_setJointMotorControl, METH_VARARGS,
 	 "This (obsolete) method cannot select non-zero physicsClientId, use setJointMotorControl2 instead."

src/BulletDynamics/Featherstone/btMultiBody.h

@@ -140,6 +140,11 @@ public:
 		return m_baseCollider;
 	}
 
+	btMultiBodyLinkCollider* getLinkCollider(int index)
+	{
+		return m_colliders[index];
+	}
+
     //
     // get parent
     // input: link num from 0 to num_links-1